1. Field of the Present Invention
The present invention relates generally to radio communication methods and systems and more specifically to analog narrow-band and spread spectrum wireless data links with interface to the public switched telephone network.
2. Description of the Prior Art
Cordless, or wireless, telephones have become very popular over the years. Analog narrow-band cordless telephone sets generally give satisfactory service within residential homes, and the more recent 900 MHz direct sequence spread spectrum (DSSS) and frequency hopping wireless equipment have extended the useful range and improved the signal quality for consumers. Many wireless data links are now also popular and are used to interface accessories to the serial ports of personal computers. But such interfacing can be inconvenient if the computer's serial port needs to be used for other devices too. So, most small computers being sold now have internal modems installed and this makes it more convenient to use the modem signal, rather that the serial digital signal, in any wireless link to other equipment.
Cordless telephone use has generally been limited in the prior art to voice communications, especially in the untethering of individual subscribers from the constraints of their wallphone or corded desk phone placements.
Portable laptop computers are now universally equipped or compatible with modems that can dial out and automatically answer calls too. Connecting a telephone cord to a battery operated laptop computer for telephone network access is also ubiquitous, but this seems odd to leash a user's freedom this way. So it now has also developed that cellular phones and maybe even cordless phones have been connected to or incorporated within laptops to once again set the user free to roam about without the limitations of wires.
Users of laptop computers very often have larger desktop computers too. So it frequently happens that such users would like to transfer a data file from one to the other. Such transfers can be done by floppy disk, if the disk systems are compatible. Or the data file transfer can be done by a wired link between the desktop and the laptop computers, but if the laptop and desktop are not very close to each other, this would usually involve the use of modems and the telephone network.